PromiseKit Versions Save

What's Changed

• func when(fulfilled thenables: [any Thenable]) by @RomanPodymov in https://github.com/mxcl/PromiseKit/pull/1321

Full Changelog: https://github.com/mxcl/PromiseKit/compare/8.0.0...8.1.0

• podspecs updated to work with Xcode 13/14
• Alamofire, Bolts and OMGHTTPURLRQ subspecs removed

Both these changes are major semantic version breakers, hence v8.

v7 was never formally released, but it was still tagged, hence we skipped v7.